The present disclosure relates to an illumination device using a light guide plate, and a display device including the same.
Typically, a liquid crystal display (LCD) used in various electronic devices such as a television, a cellular phone, a notebook PC (personal computer), and a digital camera includes a backlight illuminating a liquid crystal panel. As a backlight, for example, a light source module in which a light emitting diode (LED) is provided on a side face of a light guide plate is used. As the LED, an LED chip emitting white light is mounted on a package of heat-resistant polymer, ceramic, or the like, and used in many cases.
In recent years, by arranging such a plurality of light source modules side by side, an illumination device adaptable to a large screen size, and a so-called partial drive method has been proposed (for example, Japanese Unexamined Patent Publication No. 2008-108623).
Here, in the light source module using the LED as described above, surface light emission is performed by allowing the white light to enter inside the light guide plate from the LED, and extracting this white light from one face (light emission face) of the light guide plate. However, at that time, a part of the light emitted from the LED chip is leaked from the package side, and is emitted to the top part of the LED as it is without entering inside the light guide plate. Such leak light becomes a color light which is somewhat yellowish by transmitting the package. Thus, the yellowish light is mixed into the white light emitted from the light emission face of the light guide plate correspondingly to the arrangement place of the LED.
In the liquid crystal display for mobile applications such as a cellular phone, since the screen size is small, the light source module is used alone in many cases. Thus, the LED is arranged outside (in a frame of) a display screen, and the leak light from the LED is shielded in the frame. Thus, in the case where the light guide plate is used alone, the influence by the leak light as described above is particularly not an issue.
However, like the illumination device of Japanese Unexamined Patent Publication No. 2008-108623, in the configuration in which a plurality of light source modules are arranged side by side, the LED is disposed close to a boundary of the light guide plates. That is, the LED is arranged in a local region in the display screen. Thus, in the illumination device using a plurality of light guide plates, there is an issue that color unevenness as described above is generated close to the boundary of the light guide plates.
In view of the foregoing, it is desirable to provide an illumination device capable of performing a surface light emission by utilizing a plurality of light guide members, and suppressing generation of color unevenness, and a display device using the same.